Technologies improving the miniaturization of integrated circuit chips have advanced in response to the increasing demands for downsizing, applicability to microelectronics product functionality. Ultrasonic sensing, a modality of biometric technologies that operates on sound wave, pulse echo, etc. as a medium to sense and detect biomolecules, is an exemplar application area where the supply for miniaturized integrated circuits chips is in higher demand. In this stream of technological development, ultrasonic sensing can deliver satisfactory biometric results on levels including dermis imaging and subcutaneous three-dimensional imaging; all can be done without undesired concerns over dirt or water contamination. When compared against other biometric modalities, the deeper limit of resolution achievable by ultrasonic sensors earns this biometric structure its name as the most accurate biometric technology.
Ultrasonic sensors are a type of sensors for which small size is considered to be a crucial form factor. As such, in making semiconductor integrated circuits for ultrasonic sensors, there is a continued need to resolve the challenge in their fabrication due to long electrical transmission path between piezoelectric array and application-specific integrated circuit (ASIC) through wire bond and PCB routing, multiple layouts for piezoelectric array to ASIC connection, or large gap between cover layer and sensor due to wire bond mold.
The various features disclosed in the drawings briefly described above will become more apparent to one of ordinary skill in the art upon reading the detailed description below. Where features depicted in the various figures are common between two or more figures, the same identifying numerals have been used for clarity of description.